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Unified Modeling Language, Version 2.0

Chapter 2

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Objectives

Understand the basic characteristics of object-oriented systems.

Be familiar with the Unified Modeling Language (UML), Version 2.0.

Be familiar with the Unified Process.

Understand a minimalist approach to object-oriented systems analysis and design.

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Basic Characteristics of Object Oriented Systems

Classes and Objects

Methods and Messages

Encapsulation and Information Hiding

Inheritance

Polymorphism and Dynamic Binding

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Classes and Objects

Class – Template to define specific instances or objects

Object – Instantiation of a class

Attributes – Describes the object

Behaviors – Specify what object can do

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Classes and Objects

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Methods and Messages

Methods implement an object’s behaviorAnalogous to a function or procedure

Messages are sent to trigger methodsProcedure call from one object to the next

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Messages and Methods

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Encapsulation and Information Hiding

Encapsulation combination of data and process into an entity

Information HidingOnly the information required to use a software module is published to the user

Reusability KeyUse an object by calling methods

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Inheritance

Superclasses or general classes are at the top of a hierarchy of classes

Subclasses or specific classes are at the bottom

Subclasses inherit attributes and methods from classes higher in the hierarchy

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Class Hierarchy

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Inheritance

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Polymorphism and Dynamic Binding

PolymorphismA message can be interpreted differently by different classes of objects

Dynamic BindingSometimes called late binding

Delays typing or choosing a method for an object until run-time

Static BindingType of object determined at compile time

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Polymorphism & Encapsulation

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The Unified Modeling Language, Version 2.0

Structure Diagrams

Behavior Diagrams

Extension Mechanisms

DevelopersGrady Booch

Ivar Jacobson

James Rumbaugh

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Structure Diagram

Structure Diagrams includeClass

Object

Package

Deployment

Component

Composite structure diagrams

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UML 2.0 Diagram Summary

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Structure Diagrams

Classrelationship between classes

ObjectRelationships between objects

PackageGroup UML elements together to form higher level constructs

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Structure Diagrams Cont.

DeploymentShows the physical architecture and software components of system

ComponentPhysical relationships among software components

Composite StructureIllustrates internal structure of a class

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Activity Diagrams

ActivityIllustrates business workflows

SequenceTime-based ordering Behavior of objects activities in a use case

CommunicationCommunication among a set of collaborating objects of an activity

Interaction Overview TimingOverview of flow of control of a process

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State Machines

Behavioral State MachineExamines behavior of one class

Protocol State MachineShows dependencies of different interfaces of a class

Use-CaseCaptures business requirements

Illustrates interaction between system and environment

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Use Case Diagrams

Captures Business requirements

Illustrates interaction between a system and its environment

Includes end user

Any external system that interacts with its information system

Documents and clarifies requirements of system being modeled

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Extension Mechanisms

StereotypesGives ability to incrementally extend UML

Tagged ValuesAdd new properties to base elements

ConstraintsPlace restrictions on use of model elements

ProfilesGroup model elements into a package

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Object Oriented Systems Analysis and Design

Use-case driven

Architecture CentricFunctional View – external behavior

Static View – internal structure

Dynamic View – internal behavior

Iterative and Incremental

The Unified Process

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Engineering Workflows

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Supporting Workflows

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A Minimalist Approach

Benefits of Object-Oriented Systems Analysis and Design

Extensions of the Unified Process

The Minimalist Object-Oriented Systems Analysis and Design Approach

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Benefits of the Object Approach

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MOOSAD Approach

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Basic Characteristics of Object Oriented System

Identifying business valueAnalyze feasibilityDevelop workplanStaff the projectControl and direct projectRequirements determinationFunctional modelingStructural modelingBehavioral modelingMoving on to design

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UML Summary

Class and method design

Data management layer design

Human computer interaction layer design

Physical architecture layer design

Construction

Installation

Operations and support

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Summary

Basic characteristics of an object oriented systemUnified modeling systemObject oriented Systems Analysis and DesignMinimalist approach to Object oriented systems analysis and design with UML